The document discusses various renewable energy sources including solar, wind, tidal, geothermal, and biogas energy. For solar energy, it explains that the sun's energy reaches the Earth's surface and can be used to heat water. For wind energy, it describes how wind turbines convert kinetic energy from the wind into electrical energy. It discusses how tidal energy is generated by the moon and sun's gravitational forces and can be captured by tidal barrages. The document also summarizes that geothermal energy harnesses the Earth's natural heat below the surface and that biogas is produced from biomass and waste through anaerobic digestion. Overall, it presents renewable energy sources as sustainable alternatives to fossil fuels that do not poll

1. Energy lies in every object on the earth
:The Secret book.

2. Originates with the thermonuclear fusion reactions
occurring in the sun. Represents the entire electromagnetic radiation.
Thesurface receives about 47% of the total solar energythat reaches the
Earth. Only this amount is usable.
Twomethods of heating water: passive (no moving
parts) and active (pumps).In both, a flat-plate collector is used to absorb
the sun’s energyto heat the water.The water circulates throughout the
closedsystem duetoconvection currents. Tanks of hot waterareused as
storage.

3. Sunlight is focusedon a receivermade from
silicon or othersemi conductor which converts sunlight into electrical
DC supply .solar cells configured to make solar panel.
1.Only pure radiantenergyreaches theEarth.
2.Energy reachingthe earthis incredible.By onecalculation,30 days of sunshinestriking
theEarthhave theenergyequivalentof the totalof all theplanet’sfossil fuels, both
used and unused!
1.Sun does not shineconsistently.
2.Solar energy is adiffuse source.
3.Addressed by approachingtheproblem through:
1) collection, 2) conversion, 3) storage

5. Differential heating of the earth’s surface and atmosphere
induces vertical and horizontal air currents that are affected by the earth’s
rotation and contours of the land.
Wind power generator is attached at one end to the wind
turbine, which provides the mechanical energy. Wind power generators
convert wind energy (mechanical energy) to electrical energy.
The design of a windmill is an integral part of how efficient it
will be .When designing a windmill, one must decide on the size of the turbine,
and the size of the generator. Turbine has common design i.e. the three-bladed
turbine bcoz it provides more stability and The generator needs to have a
cooling system to make sure there is no overheating.

6. 1.Thewindblows dayandnight,which allowswindmills to
produceelectricity throughoutthe day. (Fasterduring theday)
• 2.Windenergy is adomestic,renewable sourceofenergy thatgeneratesno pollution
andhaslittle environmentalimpact.
• 3.Thewind powercostis decresing.
1.Largeturbinesdon’tturnasfast
2. Birds often collide with high voltage overhead lines, masts, poles, and windows
of buildings.
3.Some birds even nest on cages on Wind Towers.

8. Tides generated bythe combination of the moon and
sun’s gravitational forces .Greatest affect in spring when moonand sun
combine forces. Bays and inlets amplify the height of the tide.In orderto
bepractical for energyproduction, the height difference needs to beat
least 5 meters.
Firstgeneration, barrage-style tidal power plants.
Works by building Barrage to contain water after high tide, then water
has to pass through a turbine to return to low tide.

9. 1.No pollution
2.Renewable resource
3,More efficient than wind because of the density of water
4.Predictable source of energy vs. wind and solar
1.Presently costly Expensive to build and maintain
2.Connection to the grid
3.Technology is not fully developed
4.Barrage style only produces energy for about 10 hours out of the day
5.Barrage style has environmental affects
 Suchas fish andplant migration
 Silt deposits
 Localtides change-affectsstillunder study

11. The centre of the Earth is around 6000 degrees Celsius -hot
enough to melt rock. Even a few kilometres down, the temperature can be over
250 degrees Celsius. In general, the temperature rises one degree Celsius for
every 36 metres you go down. In volcanic areas, molten rock can be very close
to the surface and in such areas geothermal energy has been used for
thousands of years for cooking and heating.
Geothermal field -thermalareawhere permeable
rockformations below ground containa working fluid withoutwhichthe areacould notbe
exploited.
Geothermal field characterizations:
 Semi-thermal field- produces waterup to 100oC from drilling depths of 1-2 km
 Wet hyper-thermalfield (water-dominated)- produces pressurized water> 100oC
 Dryhyper-thermalfield (vapor-dominated)- produces drysaturated,or slightly
superheatedsteam atP > Patm

12. 1.As the U.K.is only ona semi-thermal field we
cannot rely upon its resource as a way into the future.
2.geothermal resources are not spread uniformly.
3.heat pumps are required.
1.Direct use and heating applications have almost no
negative impact on the environment.
2.Geothermal power plants do not burn fuel to generate electricity, so their
emission levels are verylow.
3. Geothermal plants emit97 percentless acid rain.

14. Afuelgasproducedfrombiomassand/or fromthe
biodegradablefractionofindustrialanddomesticwastematter,
thatcanbepurifiedandupgradedtonatural gas quality,tobeused
as biofuels,or thewoodgas. itismixtureofMethane(55%)and
CO2(30to40%).
gobarisinlet.itisfermentatedor anaerobic
digestionbybacteria.biogasisproducedinan airtightclosed
cylinder.
Anair tightclosedcylinderinsidetheearth.ithas
inletandoutlet.It’sbodyismadeofmetal witha tubeattop.

15. 1.ithasnohazardouseffectonenvironment.
2.itcanbeproducedinfieldsandevennear house.
3.alsohasbyproductas manure.
4.Decreasesthewaste.
:1.largespaceisrequired.
2.Itproducesodour
3.Itrequiresa lotoftime.
4.Itisnotclean.

17.  Thesearefreelyavailableinthenatureandare non
exhaustiblesourcesofenergy.theyhavelessrunningcost.
 Goal isto decreaseour dependenceonfossilfuels.
 Mitigatestheeffectsofacid rain,carbon dioxide,andother
impactsofburningcoal andcountersrisksassociatedwith
nuclearenergy
 pollutionfree,indefinitelysustainable.